Adjuvant intravenous sympathetic block with guanethidine in construction of arteriovenous fistulas for blood access.
A prospective randomized investigation of regional intravenous sympathetic block with guanethidine (RGB) was made in patients undergoing surgical construction of arteriovenous fistula (AVF) for vascular access. The blockade was preoperatively performed on chronically uraemic patients without previous vascular access surgery. The studied data were preoperative forearm blood flow, intraoperative fistula blood flow and flow resistance, and patency rates of AVF. Serial occlusion plethysmography showed a 152% increase in mean forearm blood flow in the RGB group, with significant (p less than 0.001) difference from the controls. The fistula blood flow resistance was decreased (p less than 0.05). The early failure rate was 1/17 among the patients treated with RGB and 3/17 in an otherwise comparable control group. RGB may be useful for reducing early failure rates after construction of AVF, by facilitating blood flow through the fistula.